code: def __sample_token(self, doc, token):
      new_topic = token.topic
      for i in range(self.__mh_steps):
          doc_proposed_topic = self.__doc_proposal(doc, token)
          new_topic = self.__word_proposal(
              doc, token, doc_proposed_topic
          )
      return new_topic
  
imports: import os
  import numpy
  from tqdm import tqdm
  from paddlehub.common.logger import logger
  from slda_weibo.document import LDADoc, SLDADoc, Token, Sentence
  from slda_weibo.vose_alias import VoseAlias
  from slda_weibo.util import rand, rand_k
label_desc: Use image node_id 4 for calling the MHSampler obj's underlying member method code with example usage: obj.__sample_token(doc, token) and returns: new_topic